To listen to David Cameron’s rhetoric this week, it could be 2001 all over again. Eleven years into the war on terror, it might have been Tony Blair speaking after 9/11. As the bloody siege of the part BP-operated In Amenas gas plant in Algeria came to an end, the British prime minister claimed, like George Bush and Blair before him, that the country faced an “existential” and “global threat” to “our interests and way of life”.

While British RAF aircraft backed French military intervention against Islamist rebels in Mali, and troops were reported to be on alert for deployment to the west African state, Cameron promised that a “generational struggle” would be pursued with “iron resolve”. The fight over the new front in the terror war in North Africa and the Sahel region, he warned, could go on for decades.

So in austerity-blighted Britain, just as thousands of soldiers are being made redundant, while Barack Obama has declared that “a decade of war is now ending”, armed intervention is being ratcheted up in yet another part of the Muslim world. Of course, it’s French troops in action this time. But even in Britain the talk is of escalating drone attacks and special forces, and Cameron has refused to rule out troops on the ground.